What is a key factor influencing dose delivery in an isocentric setup?

In an isocentric setup, patient positioning is a critical aspect that influences dose delivery. The isocenter is a fixed point around which the gantry rotates, and accurate patient positioning ensures that the target volume remains aligned with this point throughout the treatment. If the patient is not correctly positioned, the dose distribution may not adequately cover the tumor, leading to under-treatment or excessive dose to surrounding healthy tissue.

Proper patient positioning allows for precise targeting of the radiation beam, ensuring that the prescribed dose is delivered effectively to the intended area while minimizing exposure to critical structures. Factors such as immobilization devices, patient anatomy, and the reference point for positioning all contribute to the overall accuracy of treatment delivery in an isocentric setup.